Natural Selection Theory: The Natural Selection Theory is given by Charles Darwin. There are 3 principles of Natural Selection Theory
Variation, Heredity, Selection.
Explanation:
Natural Selection is the cause of evolution. The adaptation to the environment is the key to survival according to Charles Darwin.
The story behind Natural Selection is his visit to Galapagos Islands in 1835. Here he noticed the finches of different varieties in their beaks and food sources adapted to different environments i.e from different islands. This pushed him to think about those adaptations and eventually theory of natural selection.
It’s A an generation that’s the only one that makes sense because evolution is a change over time too
Butterfly shape - Each fluorine is attached to the sulfur by a single covalent bond. The SF3 molecule is very short-lived and its structure has not been determined experimentally. It is calculated to adopt a butterfly-shaped molecular geometry, belonging to the Cs point group.
Answer:
Replacing skin defects has witnessed several developments over the centuries. It started with the introduction of skin grafting by Reverdin in 1871. Since then, varieties of skin grafting techniques have been used successfully. Despite being clinically useful, skin grafts have many limitations including the availability of the donor site especially in circumstances of extensive skin loss, immune rejection in allogenic skin grafts, pain, scarring, slow healing and infection.1,2 For these reasons, scientist have worked hard to find skin substitutes to replace skin defects without the need for a "natural" skin graft. These materials which are used to cover skin defects are called "Skin substitutes". This article briefly discusses the common types of skin substitutes and their clinical uses.
